Automatic stoker



ec# 29' 1925. l 1,567,525

` E. LUNDGREN l AUTOMATIC STOKEH Filed July .27, 1922 of the type of las ' an overfeed grate 4 at EWIN LNDGBEN, 0F FEEDERCK,

Y NEERIIUG CORPORATION,

isms reni' MARYLAND, ASSGNOE, TD COMBUSTION ENGL 0F NEW YORK, N. Y., A CORPORATION OF NEW YORK.

a'ffrroara'rlc sronnn.

Application filed July?, 1922. Serial No. 577,825.

To all 'whom t may concern:

Be it known that' I, EDWIN LUNDGREN, a Citizen of the United States. residing at Frederick, county of Frederick, State of Maryland, have invented a certain new and useful Improvement in Automatic Stokers, of which the following is a full. clear, and exact description.

The present invention relates to furnaces of the type in which the' fuel While in the course of combustion is fed progressively toward a discharge outlet through which the refuse of the fuel is discharged, and has for its object to provide novel and improved fuel feeding means in :i furnace of this character.

The several features of the invention will be clearly understood from the following;r description and accompanying drawings, in- Which,

Fig. 1 is a longitudinal sectional view of a 'portion of an underfeed furnace embodying thev features of the invention in their preferred form;

Fig. 2 is a transverse sectional view taken onthe lines 2-2of Figs. l and 3;

Fig. 3 is a detail sectional elevation taken on the line 3 3 of Fig. 2; and

Fig. 4 is a detail sectional view, on an enlarged scale, taken on the line 4 4 of Fig. 3.

The furnace illustrated in the drawings is the one illustrated and' de.- scribed in the patent to Riley No. 1,322,822 dated November 25, i919. furnace comprises an '.inderfeed grate 2 and the rear of the underfced grate. The underfeed grate comprises a plurality of downwardl and rearwardly inclined retorts 6 arrangedI side by side and spaced apart, with'the outer Walls of the outer retorts spaced fromv the side Walls of the furnace. Each of the retorts is provided with a bottom wall 8 and side Walls lO. The bottom Walls 8 of the several retorts form continuations of the bottom Walls, respectively, of fuel hoppers 12 which are supported on an -b'eam 14, the fuel from the hoppers being fed into the retorts by means of reciprocating plungers 16. On the upper edge of eachof the side walls of the retorts is mounted a ron7 of tuyre blocks 18, the rows of tuyre blocks mounted on adjacent WallsV of the retort being arranged side by side with their inner surfaces in sliding engagement, and the rows oftuyre blocks As slioivn this,

mounted on the outer walls of the outer retorts extending over the spaces between the 'outer Walls and the side Walls of the furnace. The overfeedgrate is made up of :i plurality of sections arranged side by side. each of which is aociatcd with one of the side Walls of oneof the retorts and 'these parts together with the row of tn vre blocks supported -on ,the side wall are adapted to be moved t ether as a unit back andforth in a subst@ fri'ly horizontal direction so as to efect the `:eding'of the fuelv pro,fn'essivel While in the course of combustion'. and tlie discharge of the refuse of the fuel into an ash pit 20 which is located at the rear of the overfeed grate. To enable said units to be thus moved back and forth, each overfeed grate serien is mounted on a shoe 22 adapted to slide horizontally on a support 24, the lower or rear end of the associated retort side Wall being at 26 to the shoe and its upper or forward end being mounted to slide on the upper edge of the I-beam 14. The means for actuating the several movable units as above described comprise links 28. connecting the for- Ward ends of the side walls of each retort with the feeding plunger 16 associated with the retort. Each of the shoes 22 cari the upper 0r forward end' of a refuse discharging device 30 which extends downwardly into the ash pit 2O and cooperates with a clinker crushing roll 32 mounted in the ash pit. Except as hereinafter described, the parts above referred to may be and preferably are the same as corresponding partsof the Stoker illustrated and described in said patent; to Riley No. 1,322,822'to which ref@ erence nia",r be had for a more complete deseription of the same.

In said patented construction the movable units comprising the side Walls of the retorts and their respectiva,1 rows of tuyre blocks and overfeed grate sections, have the same fuel aoitating and feeding action at the for Ward portion of the fuel beda as at the rear portion thereof, which is objectionable, articularly in furnaces having relatively ong retorts, as it is necessary in orderto secure the maximum etciency of performance that thefuel agitatingI and feeding action shall be greater att-he forward portion of the fuel bed than at the rear portion. In order to overcome this disadvantage of said prior construction each of said movable units of pivotally connected itil fifi

Mil

the rear section, said connection between theA sections having provision for adjustment to i vary the difference of the amplitude of the movements of the two ,sectionsv to meet difl l .o That I claim is:

ferent conditions. As shown, each of the side walls of the retorts is divided transversely in a horizontal plane as indicated i: at 32 into two Ysections 34 and 36. The forward end of each rear section 36 is mounted on I-beams 40 extending between the si'de walls of the furnace, the lower edge of the e section having a horizontal lportion 38 1n- 2Q sliding engagement with the' tops of the I- f beams. The rear end of the forward section 34 is supported by theforward end of the section 36, the lower edge of the forward section having dependingguiding flanges Z5. 42 at theline of division between the sections which engage inwardlyl turned flanges 44 on the upper edge of the associated rear section 36. The connections between the sections 34 and 36' of each side wall of the retorts comprises a depending lug 46 on the out/er side of the forward section 34 which fis interposed between two spaced abutment 'screws 48'that are screw-threaded through 1 lugs 50 o i the rear section 36. With this constructi -it will be apparent that upon actuation of the'. reciprocatingplungers 16 to feed the fuel from the hoppers 12 into the retorts that back and forth movements will be imparted to the several forward secv4A) tions 34 and tothe tuyre blocks'supported- A thereby, and that back and foith`movements of less amplitude will be imparted to the several rear sections 36, to the tuyre blocks supported thereby and to their associated 46 'overfeed grate sections. By adjusting the abutment screws 48 the lost motion between the sections and consequently the difference in the amplitude of the movements imparted to the forward and rear sections 34 and 36 50 of each side wall of'ythe retorts may be varied as desired.

' up of but two movable sections, the invention is not confined to a two section construction of the underfeed grate, 1t ,being only necessary that there shall be at lease two such sections; and also that my inven- 4 tion permits of various modifications with-v out departing .from the'spirit thereof or the scope of the appended claims. v

1. A. furnace having, in combination, an linderfeed grate and -an overfeed 1ate at the rear of the underfced "grate, sai underfeed grate having two sections arranged one behind the other and movable longitudinally of each other, connections between the rear section and the overfeed grate so as to cause them to move together, means for imparting a back and forth'movement to one of said sections, and connections between said sections-for imparting a back and forth movement tothe other section of 'a different amplitude than said movement imparted to theformer section.

2. A furnace having, in combination, an underfeed grate, an overfeed grateat the rear of the underfeed grate, said underfeed grate having two sections arranged one behind the other and movable longitudinally of each other, connections between the rear Section and the overfeed grate, and means `for imparting a back and forth movement to said sections having provision for adjustment to vary the amplitude of the movement of one of said sections with relation to the other section.

3. An underfeed furnace having means for supporting .and feeding fuel while in the course of combustion comprising a down- 'ward/ly inclined retort having each of its side walls divided ti-ansversely into two sections, one 'section of each wall being movable longitudinally with relation to the other, tuyre structures mounted on each of the side walls, and means for imparting e. baci:A

and forth movement to said movable section with relation to the other.

EDWIN LUNDennN. 

